Compressed-air suspension for vehicles.



DBLPEUQH. COMPRESSED AIR SUSPENSION FOR VEHIGL APPLICATION FILEILDEG. 17, 1908. 009,287.. Patented Nov. 21,1911.

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- UNITED srarus PATENT OFFICE.

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COMQI'R-ESSED-AIR SUSPENSION. FOR VEHICLES.

. Be it known that I, Lr'zon DELPEUCH, a citizen of the Republic of France, residing Department of the Seine, France, have invented certain new, and useful Improvements in Compressed Air Suspensions for Vehicles, of which the following is a specification.-

This invention relates to an improved compressed air suspension applicable to vehicles ,of all kinds, including aeroplanes.

'The said suspension is mtended to replace the springs usuallyemploye I It comprises compressed air cushlomng devices equal/n number to the wheels, a

cushioning device being interposed, $11111 -larly 'to a spring,

between an end of the axle and the frame of the vehicle.

In thesystems of compressed air suspension which have reviously'been employed, the compressed cushion sudden shocks or viibrations; but

the expansion of the mass of air thus subjected tofa shock takes place as rapidly as 'thashock itself, so that counter shocks are produced which interfere with the comfort of thepass'engers and strain the motor or other parts of the vehicle just as much as direct shocks. '3 g The improved apparatus .comprises the below. the piston of each cushof a spring which is compressed and oflt'ers a resistance or back pressure when vits cylinder rises as the resultof paratus. 1

excess load or stres sat the other side of the vehicle, that is to say at the opposite end of the axle; consequently this spring assists librium.

in righting the vehicle and restoring equi-- f gards its cushioning. action.

The improved compressed air suspension, will be understood from the following de? Figure 1 is a diagrammatic plan of the system, Fig. 2 is a-vertical section of one'of the cushioning devices. Figs. 3 and 4 are diagrams illustrating the action of the ap- For each wheel, that is to say at each end of the axles is provided a cushioning'device comprising a cylinder A fixed vertically to the side of-the frame B. In this cylinder works a piston C guided by a rod athe lower end of which is supported on the axle in any suitable way. The cylinder A is open at bottom and closed at top. Under the piston Specification of Letters Patent.

air serves 1n reality only to. pressed air Patented Nov. .21, 1911.

' App1ic ation fil ed December 17, 19Q8. Serial 110,468,089.

1. and between same and mounted a'coiled spring R. The upper part of the cylinder .A above the piston 0 communicates by a pipe 0 with a compressed air receiver Zcommon to the two cushioning cylinders of one axle. d is a'valve fitted in the pipe 0 and kept against its seat by-a spring c. This valve is adapted to uncover the openings f when the space of the cylinder is driven back by this reductioh of volume can pass through the openingsf into the pipe c and receiver Z. a passage 9 of reduced section adapted to allow of the-return of the expelled air under 1 the conditions 'her'einafter' explained.

If desired all four cushioning cylinders of the vehicle may be connected to one comreceiver by their: pipes 0, but it is preferable to couple them in pairs to one cylinder for each axle as described, especially in cases where the weight'of the vehicle cannot be uniformly distributed. The action is moreover the same whatever may be the number of the receivers Z.

a bross piece 6 fitted across the open end of the cylinder A is '70 The valve (1 is formed with o When a wheel is subjected to a shock owing to an obstruction or an inequality in the road, so that the pistonC rises in-the cylin der,' the valve d opens andjthe air in the cylinder above therpistonis thus at once put into communication with the receiver Z."-

The total volume of air which is thus subjected to the shock being much" greater-than that contained in the suspension proper, that is to' say in the cylinders A, the systemsas a whole is very responsive and supple as re- The :consequence is that the pressure in the cylinder operation at a given moment does not rise suddenly, as would be the case if, the different cushioning devices were independent of each other, and were not connected to one or more receivers ofxrelatively large volume as compared with that of the cylinder A. 1

, When the obstacle is cleared, the piston 0 would tend to return to its original position by reason of the air pressure exerted above it, and it might return very rapidly to this position .of equilibrium as is thevc'ase with the springs at present employed, thus causing a counter shock and vibrations as detrimental as a direct shock to themechanism and the comfort of the passengers. But the plane.

' vehicle,

valve d has now come upon" its seat, so that the air can only return slowly and gradually into the cylinder from the receiver Z through the small passage 9 in the valve. This passage may be formed in the wall of the cylinder itself instead of in the valve.'

A system comprising a number of cushioning cylinders, as above described can support different loads. When the load on the vehicle is increased it is only necessary to increase the pressure in the receiver or receivers Z by means of any suitable pump.

In order to make good any loss of air which might occur an air pump or pumps maybe disposed between the frame and one or more of the axles, so that whenever a jolt occurs air is forced into the receiver or receivers Z. Further a valve may be provided within reach of the driver to enable him to reduce the pressure in the receiver or receivers Z without dismounting from the and a pressure gage can be provided in connection with the receiver or receivers to indicate the pressuretherein.

The coiled spring R fitted in each cushioning device between the' piston and the cross piece 6 in which the piston rod is guided, is not normally in action; the to coil of this spring hardly touches the bottom of the piston C. In order properly to understand the part played by this spring in each of the cylinders connected to a given receiver Z, supose each of these springs to have a resistance of 100 lbs. and suppose that the line M. N (Fig. 4) represents the normal level of the frame of the vehicle and that the frame has tilted into the position M N. The two pistons C C of the cylinders of one axle will have remained in their previous position, i. e. in one horizontal But' cylinder A has moved down and cylinder A has risen. The bottom of piston C in cylinder A is therefore away from the spring, which has moved down with the cylinder A. Air above the piston C has been compressed and forced out of the to the cylinder'toward the receiver Z, it Will return slowly into the cylinder through the pas-.

sage g of valve 03 asbefore explained and the frame will reassume its normal level.

At the same time the other cylinder A has risen, the resultof which is to introduce the efiect of a momentary excess load at the-op-' posite sideof the vehicle viz. that at which the cylinder C is mounted.

The spring R therefore acts In the foregoing description the cylinders are assumed as fixed to t'heframe and the piston rods as connected to the axles. It will be understood that with the same method the cylinders could be supported on theaxles and the pistons be connected to the frame.

What I claim and desire to secure by Letters Patent is:

A compressed air suspension for vehicles comprising cushioning devices equal in number to the wheels of the vehicle, and comprising pistons and cylinders connected one to the frame and the other tothe axle, a spring in each cushioning device applied under side of the piston and to the bottom expansion of the air and reacting so as to increase the pressure in the reservoir and to transmit this pressure to the opposed cushioning device, rium where the vehicle is excessive load. v

In witness whereof, I have hereunto signed my .name in the presence of two subinclined un er an scribingwitnesses.

LEON DELPEUCH.

. V Vitnesses:

HANsoN O. Come, GABRIEL BELLIARD.

whereby to reestablish e uilib- 

